JPH07223453A - Quick change type power take-off mechanism with breakaway type collar - Google Patents

Abstract

PURPOSE: To provide a power take-off assembly which allows rapid and easy conversion to a different operating speed. CONSTITUTION: A power take-off assembly for a working vehicle includes an output drive member which can be driven at various speeds and power levels and an output shaft for connection to the output drive member. A hollow, cylindrical breakaway drive collar 122 includes a first end having a first set of splines 126 which mesh with the corresponding splines of the output shaft, a second end having a second set of splines 124 which meshes with the corresponding splines of the output drive member, and a central neck portion 128 located between the first and second ends. The neck portion 128 is formed so that a drive collar 122 ruptures at its neck portion 128 as a result of accumulation of damage caused by torque and prevents transmission of torque to the output shaft, and so that the drive collar ruptures prior to rupture of the output shaft. A bearing assembly is fixed with respect to the vehicle and rotatably supports the output shaft.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to power take-off or "PTO" mechanisms such as those used in agricultural vehicles.

[0002]

2. Description of the Related Art A high-power (large horsepower) type agricultural tractor (greater than 155 horsepower) is about 44.5 mm (1 horsepower).
1000 rpm PT with diameter of 3/4 inch)
Only those with an O output shaft are produced. Such a tractor has a smaller size of about 34.9 mm (13 /
8 inch diameter 540 rpm and 1000r
The standard size shaft of pm is not provided, because
Such a shaft is not capable of transmitting the full power output of a tractor of that size.
The most common size instrument PTO shaft size is about 34.9 mm (1/8 inch). Currently, in order to use such equipment, a clamp-on type (pressing type) adapter is used for the output shaft of the tractor, or a drive for such equipment is used.
It is necessary to change the line (power transmission system) so that such equipment can be used for large tractors. Clamp-on type shafts need to be run at low engine speeds to provide the proper PTO speed when converted to the standard 540 rpm spline. Low engine speeds are not acceptable for operations that require high traction force to pull the tow bar, as well as for PTO operation. Several low power reduction gearboxes are available to compensate for the proper output speed. Such gearboxes are expensive, require cooling oil external plumbing lines for harsh use, and do not meet acceptable position guidelines for instrument attachment points. Some industrial tractors are equipped with a PTO mechanism that has a speed-selective gear mechanism that allows the speed to vary depending on which end of a double-ended PTO shaft is inserted into the PTO mechanism. You can choose.
A clamp-on design for 540 rpm and 1000 rpm splines can transfer full engine power to a small 13.8 inch shaft, in which case premature failure occurs. Will occur. Changing the drive line of an instrument to match a tractor is expensive, complicated, and time consuming. Also, if excessive torque is applied to a shaft or equipment that is not designed for such torque, parts will break and a dangerous situation will occur. If the device is designed to limit the maximum torque level that can be transmitted, such a design seems unacceptable to the user. Designing the coupler (connecting means) so that it does not transmit torque above the failure design limit of the shaft will result in a coupler that very often fails and is annoying to the operator.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a PTO mechanism that can be quickly and easily converted to different operating speeds with a properly sized output shaft.

Another object of the present invention is a PTO that will fail in a controlled manner when excessive torque is applied.
It is to provide a mechanism.

[0005]

SUMMARY OF THE INVENTION The above and other objects are for a power take-off assembly for a work vehicle, an output drive member capable of being driven at various speeds and power levels, and an output connected to the output drive member. And an axis. The hollow cylindrical drive collar has a first end having a first set of splines that engages a corresponding spline of the output shaft and a second end that has a second set of splines that engages a corresponding spline of the output drive member. The end of
A central neck portion located between the first and second ends. The neck portion breaks at its neck portion as a result of damage due to accumulated torque, preventing transmission of torque to the output shaft, and the drive collar breaks before the output shaft breaks. Is configured as follows. A bearing assembly is fixed with respect to the vehicle to rotatably support the output shaft.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a spline type engine driven shaft 12
Shows a prior art PTO mechanism 10 connected to
The spline engine driven shaft projects outward from the frame portion 14 of an agricultural tractor or work vehicle (not shown). The input gear member 16 includes a hub 18 splined to the shaft 12, a set of central splines or gear teeth 20, and a set of outer gear teeth 22 facing radially inward. Carrier housing 24
Are attached to the hub 18 via bearings 26. An output housing 28 is secured to the tractor frame or housing portion (not shown). The carrier housing 24 is provided with bolts (not shown),
It is also attached to the housing 28. The counter shaft gear member 30 includes a bearing 32 in the housing 24,
In addition, it is rotatably supported by a bearing 34 in the housing 28. The counter shaft gear 30 is
It comprises a set of gear teeth 36 having a large diameter and a set of gear teeth 38 having a small diameter. The output drive gear member 40 has the gear teeth 3 of the counter shaft gear member 30.
It has an outer gear 42 and an inner gear 44 that mesh with each other.

A hollow sleeve 46 is rotatably housed within the axial center hole of the output drive gear member 40. The inner portion of the sleeve 46 has an outer spline 48. The outer end of the sleeve 46 has an inner spline 50. A transverse hole 52 extends radially through the inner portion of the sleeve 46. The inside of the sleeve 46 defines an inner bore 53 having a smaller diameter and an outer bore 53 having a larger diameter connected to the bore 53 by holes 54 and 55.

An annular shift collar 60 having an inner spline is axially slidably mounted on the outer spline 48 of the sleeve 46. A radial hole 62 extends through the shift collar 60 and houses a spring pin 64 housed in the hole 52. The diameter of the hole 52 is larger than the diameter of the spring pin 64 so that the shift collar 60 and the spring pin 64 can slide axially with respect to the sleeve 46. The shift collar 60 has a first set of gear teeth 66 and a second set of gear teeth 68. A spring 70 is housed in bore 53 which engages the end of sleeve 46 and spring pin 64 and biases shift collar 60 to the right as viewed in FIG. Has been done.

Plunger 70 has a body 72 slidably housed in bore 53 and a stem 74 projecting into bore 54. The cap 76 allows the main body 72 to have the hole 5
Hold in 3. A groove (not shown) for engaging the spring pin 64 is formed at the end of the main body 72. The cap 78 can be pinned to the housing 28.

As shown in FIG. 1, the first output shaft 80 of the PTO can be mounted within the sleeve 46. The output shaft 80 has an outer end 82 with a splined outer end having a standard diameter of about 44.5 mm (13/4 inch) used to provide a drive force of 1000 rpm to the instrument. Is equipped with. Shaft 80 includes an inner portion that has a small diameter end portion 84.
And a portion 86 having an intermediate diameter and a portion 88 having a large diameter, the large diameter portion 88 having a spline that mates with the inner spline 50 of the sleeve 46. An annular shoulder 90 connecting the portions 84 and 86 is a shoulder 9 formed on the sleeve 46.
2 to prevent the inner end of the shaft 80 from engaging the stem of the plunger 70.

Removing shaft 80 from sleeve 46, FIG.
The shaft assembly 100 shown in FIG. Shaft assembly 100 is adapted to operate at a lower horsepower or power level than shaft 82. The shaft assembly 100 includes a double-ended shaft member 102 rotatably housed in a bearing 104 provided between oil seals 106 provided in a bearing housing 108. Housing 108
Can be bolted to the housing 28 with four bolts 110. A portion 112 of the shaft member 102 has a spline shape and dimensions such that it drives at a standard speed of 540 rpm. An axial blind central hole 114 extends into the end of the shaft portion 112. The other portion 116 of the shaft member 102 is 1
It has a spline shape and dimensions such that it is driven at a standard speed of 000 rpm. Shaft portions 112, 116
Identical spline sets 118 and 120 are formed at the inner ends of the respective lines. The bearing housing 108 is configured to position the rear ends of the shafts 112, 116 in proper position with respect to the connecting portion (not shown) of the equipment (not shown).

In accordance with the present invention, the hollow, annular breakaway drive collar 122 includes an inner spline 124 for mating with the spline 118 or 120 and an outer spline 126 for mating with the spline 50 of the sleeve 46. ing. As best shown in FIGS. 3 and 4, drive collar 122 also includes splines 12.
A neck portion 128 located between 4, 126 and having a small diameter is also provided. A plurality (preferably four) of uniformly spaced holes 130 extend radially through the neck portion 128. The collar 122 is preferably formed from a material that is structurally weaker than the material of the other elements involved, such as nodular cast iron material or 4
It can be formed from 140 steel.

The shaft portion 112 can be inserted into the sleeve 46 and the spline 126 of the drive collar 122 can be engaged with the spline 50 of the sleeve. In this case, the power is input gear member 16, shift collar 6
0 and the sleeve 46, and is transmitted from the drive shaft 12 to the shaft 102 at 1000 rpm.

The shaft portion 116 is inserted into the sleeve 46 to engage the end of the shaft portion 116 with the stem 74, thereby allowing the plunger 70, the spring pin 6 to engage.
4 and shift collar 60 to the left to press spline 6
6 can be disengaged from spline 22 to engage spline 68 with spline 44 of output drive gear 40. In this case, the motive power is the input gear member 1
6, through the counter shaft gear member 30, the output drive gear member 40, the shift collar 60 and the sleeve 46, the power is transmitted from the drive shaft 12 to the shaft 102 at 540 rpm. Therefore, by simply inserting one or the other end of the shaft member 102 into the sleeve 46, the shift collar 6
By moving 0, an appropriate drive speed can be obtained.

The neck portion 128 has a small diameter, and
Due to the holes 130, torque damage
It will accumulate in the collar 122 at a faster rate than it accumulates in the output shaft. As a result, the collar 122 breaks faster than the output shaft breaks. The drive collar 122 typically breaks as a result of cracks that occur in the neck portion 128 and spread circumferentially around the neck portion 128. Such breaks generally preferably occur at the neck portion 128 near a plane orthogonal to the central axis of the drive collar 122. When such a break occurs, no torque is transmitted to the outer end of shaft 102. This prevents the outer end of the shaft 102 from rotating and prevents damage to other parts of the shaft 102 on the downstream side.

The collar 122 does not limit the level of torque that can be transmitted. The collar limits the number of peak torques that can be transmitted and, as mentioned above, fatigue damage accumulates there at a much faster rate than the material used for the output shaft or parts of the equipment (not shown). Designed to be. This allows the user to transfer a high level of torque to some high inertial device to start it, or to stop other devices. The collar 122 is preferably designed as the first part to break to alert the user that the safe operating limits of the shaft he is using have been exceeded. The life of the collar 122 should be such that multiple collars break before the shaft breaks. If the operator continues to break multiple collars operating beyond the capabilities of the equipment's driveline, then the driveline must be converted to a driveline with higher torque capability.

The design of the collar is based on the concept of fatigue damage. This means that the generation of torque above a certain level will accumulate. For example, the production of one high torque accumulates the same amount of damage as the production of many lower torques. The collar is designed to require less damage build-up than the shaft before its fracture.

Although the invention has been described with reference to specific embodiments, it should be understood by those skilled in the art that many alternatives, modifications and variations will be apparent based on the above description. Accordingly, the present invention is intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims.

[Brief description of drawings]

1 is a prior art PTO on which the present invention is intended to function.
It is a fragmentary sectional view of a mechanism.

FIG. 2 is a partial cross-sectional view of a double-ended PTO shaft assembly constructed in accordance with the present invention.

FIG. 3 is an enlarged view of the driving collar of FIG.

4 is a cross-sectional view taken along the line 4-4 of FIG.

5 is a double-ended P of FIG. 2 assembled into the structure of FIG.
FIG. 8 is an end view of the TO shaft assembly.

[Explanation of symbols]

 10 PTO mechanism (power take-off mechanism) 100 PTO shaft assembly 102 shaft member 104 bearing 108 bearing housing 112, 116 shaft portion 118, 120 spline 122 drive collar 124 inner spline 126 outer spline 128 neck portion 130 hole

Claims (10)

[Claims] 1. A power take-off assembly for a work vehicle comprising an output drive member drivable at various speeds and power levels and an output shaft connected to the output drive member, wherein the corresponding spline of the output shaft. A first end having a first set of mating splines, a second end having a second set of splines mating with a corresponding spline of the output drive member, and the first and second ends. A hollow cylindrical drive collar having a central neck portion located between the two ends, the neck portion breaking the drive collar at the neck portion for transmitting torque to the output shaft. A power take-off assembly, characterized in that it blocks and the drive collar is configured to break before the output shaft breaks. 2. The power take-off assembly of claim 1, wherein the central neck portion has a diameter less than the diameter of the first and second ends. 3. The power take-off assembly of claim 2, wherein a plurality of holes extend radially through the central neck portion. 4. The power take-off assembly of claim 1, wherein a plurality of apertures extend radially through the central neck portion. 5. The power take-off assembly according to claim 1, wherein a bearing housing is attached to a housing fixed with respect to the frame of the work vehicle, the bearing housing rotatably supporting the output shaft. A power take-off assembly characterized in that 6. A power take-off assembly for a work vehicle comprising an output drive member drivable at various speeds and power levels, and an output shaft connected to the output drive member, the corresponding spline of the output shaft. A first end having a first set of mating splines, a second end having a second set of splines mating with a corresponding spline of the output drive member, and the first and second ends. A hollow cylindrical drive collar having a central neck portion located between two ends, the neck portion being configured to apply a torque greater than a certain amount to the drive collar. Breaks at the neck as a result of circumferentially extending cracks around the neck and prevents transmission of torque to the output shaft, and the drive collar is A power take-off assembly configured to break before the output shaft breaks. 7. The power take-off assembly of claim 6, wherein the central neck portion has a diameter that is less than the diameter of the first and second ends. 8. The power take-off assembly of claim 7, wherein a plurality of holes extend radially through the central neck portion. 9. The power take-off assembly of claim 6, wherein a plurality of holes extend radially through the central neck portion. 10. The power take-off assembly of claim 6, wherein a bearing housing is mounted to a housing fixed with respect to the work vehicle frame, the bearing housing rotatably supporting the output shaft. A power take-off assembly characterized in that